Norman Brooks
45 Cal.
What is the dimensions for the various jug chokes for 12 a gauge?
Jug Choke Spec.?
- Thread starter Norman Brooks
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No one with more knowledge than me is answering so all know is a full jug choke on a 12ga has an expansion chamber of around .025 over bore size. Mike Brooks said he liked a full choke chamber to be closer to .035.
Norman Brooks
45 Cal.
Thanks, any idea of the length, entry and exit angle?
I have seen the specs on line but don't remember where.
Brokennock
Cannon
So for different gauges have a different size over bore? Is there a percentage?
Like, what percentage larger is .025" larger than the average 12 gauge bore?
Can this percentage then be applied to other gauges?
Norman Brooks
45 Cal.
I think I did too, just can't find them now. Thanks
It is my understanding that the expansion chamber size is consistent across all calibers. I am NOT an expert on jug choking and have only had two barrels choked by Caywood.
One barrel is a 40 yard turkey gun one is a 25 yard turkey gun, both barrels are identical Colerain D weight fowler barrels. The fact is that one barrel shoots a tighter pattern than the other points to a slight variation in how the jugs were cut.
I found this from a guy who cuts his own jug chokes;
A full choke requires a recess only about .020" deep, modified about .010-.015" deep and improved cylinder only about .005-.010" deep.
One barrel is a 40 yard turkey gun one is a 25 yard turkey gun, both barrels are identical Colerain D weight fowler barrels. The fact is that one barrel shoots a tighter pattern than the other points to a slight variation in how the jugs were cut.
I found this from a guy who cuts his own jug chokes;
A full choke requires a recess only about .020" deep, modified about .010-.015" deep and improved cylinder only about .005-.010" deep.
Last edited:
Larry Akers
40 Cal.
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There is no set amount of material to remove for a jug choke. The procedure is to ream a LITTLE and go pattern the gun. Repeat until the pattern is uniform. I found that at a point in reaming my improving patterns got worse. I theorized that as the wad column (which was shorter than the jug length) entered the choke the jug allowed pressure to flow around the wad column and "stir" up the shot. My gun was a 12 ga. so I got a 3/4" arc punch and punched some slugs from an old leather belt and loaded one after the over-powder wad. My theory was the over-sized leather wad would compress enough to fit down the 12 ga. tube but expand to fill the jug. It worked! I have very even modified patterns.
Norman Brooks
45 Cal.
That makes sense on the wad column, a little reaming goes a long ways. And the length of the jug choke would also play into the pattern along with what over powder wad thickness and material being used. I knew this was not going to be simple. Thanks Larry
I should point out that both the barrels mentioned are loaded with a Skychief load. I have the 25 yard gun and gave the other barrel to a friend who says his fowler shoots as tight as an after market modern turkey coke, he loads the Skychief load as well.
Before I used the Skychief load I was very disappointed in my guns pattern.
It looks pretty good now.
Before the Skychief load.
After
Before I used the Skychief load I was very disappointed in my guns pattern.
It looks pretty good now.
Before the Skychief load.
After
Norman Brooks
45 Cal.
I am not a shotgun guru so you will have to explain what a skychief load is. The last time I done anything with a ML shotgun I got disappointed and sold the double barrel and all the loading stuff with it. I am now building a 73cal./12gauge flinter a thought it would be nice if I could shoot both shot and round ball out of it. Thanks Eric.
Brokennock
Cannon
The above is good, straight from the source.
Maybe this will help too.
https://www.muzzleloadingforum.com/threads/your-skychief-load-in-pictures.121544/Note that the paper shot cup is not an original part of the Skychief load process.
Norman Brooks
45 Cal.
Thank you Robin Henderson and Brokennock. That will give me a starting point. I like the idea of the paper shot cup...
I tried paper shot cups and had way too many of them slug and not open up.
Norman Brooks
45 Cal.
Looks like I will be doing some experiments when I get the gun finished!!
Thanks everyone for the input...
Thanks everyone for the input...
Brokennock
Cannon
If you are going with a jug choke, you can try the shot cup,, but, I would probably skip it. At least not the kind of pre-made cup/cartridge I usually use for squirrel hunting.
The principle behind jug choking is to let the shot load start to open up as it enters and passes through the expansion chamber.
